Copper Plating Through Holes
For plating through holes I use the solution available at Caswell Electroplating.
Use the Bright Acid Copper Plating method, not the Flash Copper method.
I didn’t purchase the entire kit, but only the chemicals to make up the solution.
I mix the solution in a Snapware container. I use some J-Hooks from Lowes to hang the copper anode in the tank and to hang the board I am plating in the tank. I use an aquarium air stone for aeration and a Kapco Power Supply for the current. I do not use any heat, just standard room temperature.
It all works very well.
- 1 Pack Copper Crystals (Makes 1.5 Gals)
- 1 x 1.5oz Copper Brightener A
- 1 x 4oz Copper Brightener B
I mix up ½ of the solution for my size Snapware container.
- Pour 88 fl oz or 2.6 liters of distilled water into the tank. I actually use a 4 liter beaker for this mixing process but the tank will work.
- Add ½ of the copper crystals (1.25 pounds).
- Add 8 ounces or 236 mL of battery acid
- Add .75 oz or 22 mL of the Copper Brightener part A.
- Add 0.15 oz or 4.4 mL of Copper Brightener part B
I actually use a 10 mL syringe to measure the two parts of Copper Brightner and a small graduated cylinder to measure the battery acid. But you can convert the measurements to teaspoons and tablespoons and still get accurate results.
The Copper Brightener Part B is consumed by the system. So you need to occasionally add some small amounts. 2 mLs every 10 or so boards is sufficient. Technically you add 1 quart of Part B per 2000 amp hours. That’s .5 mL per hour or 1 mL every 5 boards.
I have been using the 4x8 inch copper anodes and bandages available on the Caswell web site. I cut the anode to a length to fit into the tank, then drill two holes in it and mount it to plastic j-hooks using nylon machine screws. All available at Lowes. Then I wrap the bandwage around the anode and secure it with plastic zip ties. This prevents the solution from being trashed with small bits of copper as the anode disintegrates.
I found using a plating mask reduces the surface area to an area small enough to easily plate with this small tank.
Currently with this setup I plate for 6 minutes at 6 amps of current, then I flip the board on the Y-Axis and plate another 6 minutes at 6 amp. I’m getting perfect through hole plating.
See the following areas for the complete process.